Velocity Graphs IB PHYSICS MOTION What is Speed

Velocity Graphs IB PHYSICS | MOTION

What is… Speed The rate of change of position “how fast” Velocity Speed with direction

What is a Vector? A Vector is a quantity that includes both direction and magnitude

Vector vs Scalar Vector Quantities Scalar Quantities Displacement Distance Velocity Speed Force Energy Can be negative to indicate direction Only Positive

Velocity An object not moving 3 7 2 6 1 5 0 Time 4 -1 3 -2 2 -3 1 Position 0

Velocity An object moving forward 3 7 2 6 1 5 0 Time 4 -1 3 -2 2 -3 1 Position 0

Velocity An object moving backward 3 7 2 6 1 5 0 Time 4 -1 3 -2 2 -3 1 Position 0

Velocity Showing Velocity 3 7 2 6 1 5 0 Time 4 -1 3 -2 2 -3 1 Position 0

Velocity Speeding Up (moving positive) 3 7 2 6 1 5 0 Time 4 -1 3 -2 2 -3 1 Position 0

Velocity Speeding Up (moving negative) 3 7 2 6 1 5 0 Time 4 -1 3 -2 2 -3 1 Position 0

How are these Similar? v v t Getting faster because velocity is getting farther from zero t

Velocity Slowing Down (moving positive) 3 7 2 6 1 5 0 Time 4 -1 3 -2 2 -3 1 Position 0

Velocity Slowing Down (moving negative) 3 7 2 6 1 5 0 Time 4 -1 3 -2 2 -3 1 Position 0

Velocity vs Time Graphs Which graph(s) represent an object moving in the negative direction? Which graph(s) represent an object slowing down? 0 1 2 3 4 5 6 Time (s) 2 1 0 -1 -2 -3 0 1 2 3 4 C 3 Velocity (m/s) 2 1 0 -1 -2 -3 B 3 5 6 Time (s) 2 1 0 -1 -2 -3 0 1 2 3 4 D 3 Velocity (m/s) A 3 5 6 Time (s) 2 1 0 -1 -2 -3 0 1 2 3 4 5 6 Time (s)

What is… Velocity change in position over time “speed with direction” Acceleration change in velocity over time

Types of Acceleration Speeding Up Slowing Down Changing Direction

Acceleration is Related to Force Velocity (m s-1) 30 25 0 -30 m s-1 in 10 seconds 20 15 10 5 0 -30 m s-1 in 2. 5 seconds 1 2 3 4 5 6 7 8 Time (s) 9 10 11 12

Acceleration | Slowing or Speeding? When the acceleration is in the same direction as the velocity speeding up the object is _______ When the acceleration is in the opposite direction as the velocity slowing down the object is _______ “Foot on the Gas” “Foot on the Brake” v a v a

Lesson Takeaways q I can describe the difference between speed and velocity q I can compare the difference between a vector and scalar quantity q I can plot constant velocity on a velocity vs time graph q I can plot changing velocity on a velocity vs time graph q I can use a velocity vs time graph to identify if an object is moving in the positive or negative direction as well as if it is speeding up or slowing down q I can define acceleration in terms of velocity